Armature hinge construction for electromagnetic devices



April 14, 1964 E. E. SEBESTA 3,129,363

ARMATURE HINGE CONSTRUCTION FOR ELECTROMAGNETIC DEVICES Filed Aug. 31, 1961 INV EN TOR.

EDWARD ESEBESTA United States Patent 3,129,363 ARMATURE HINGE CONSTRUCTION FOR ELECTROIVIAGNETIQ DEVKIES Edward E. Sebesta, Edina, Minn, assignor to Minneapolis-Honeywell Reguiator Company, Minneapolis,

Minn, a corporation of Delaware Filed Aug. 31, 1961, Ser. No. 135,256 4 Claims. (Cl. 317-198) This invention relates to electromagnetic actuating devices of the type having an armature hinged to a magnetic frame portion for movement through a plurality of positions in response to energization of the electromagnet. More particularly, the invention is directed to a novel arrangement for hinging the armature of an electromagnetic relay where the armature itself forms part of the hinge mechanism and wherein no separate hinge member is utilized.

In the manufacture of electromagnetic devices of the type previously described, it has heretofore been generally necessary to provide a separate hinge member attached to the armature of the relay for engagement with projecting portions of the magnetic frame member. This hinge member has been constructed of a material such as Phosphor bronze and provided surfaces which yielded substantially point contact engagement with the extending portions of the frame member to provide a hinge action therewith. The hinge member further provided a projecting portion for connection with a spring member to normally bias the armature member to an open position. The use of a separate hinge member resulted in additional costs, first due to the cost of material for the hinge member itself, and secondly, in production costs due to the need for assembling the hinge member with the armature. It has therefore been found very desirable to eliminate the hinge member altogether and to provide an arrangement wherein the armature itself serves as a portion of the hinge. This results in a substantial reduction in production costs which is particularly significant where the device is mass produced as is the case with the assignee of the present invention wherein the relay is produced in the range of several million units per year.

In an effort to obtain such a cost reduction many attempts have been made to eliminate the need for a separate hinge member. Prior to my invention this was done by providing apertures of rectangular, round, or other conventional shapes in the armature to accept the extended portions of the frame member. While a hinge action was obtained, each of these arrangements was found to be unsatisfactory in that there resulted high residual magnetism in the unit and high frictional effects. My invention provides apertures of a novel shape which overcome these objectional effects and hence render elimination of the separate hinge member possible.

It is therefore one of the objects of this invention to provide an inexpensive and reliable arrangement for hinging the armature in an electromagnetic actuating device.

Another object of the invention is to provide a hinge arrangement for an electromagnetic device wherein the armature itself forms a part of the hinging mechanism to eliminate the necessity of using a separate hinge member.

I A further object of the invention is to provide, in an electromagnetic actuating device, an arrangement for hinging the armature wherein the armature has a plurality of apertures of novel shape therein which cooperate with extended portions of a magnetic frame member of the device to provide the desired hinge action.

A still further object is to provide a hinging arrangement as previously described which eliminates the presence of high residual magnetism and large frictional effects in the device.

saaassa Patented Apr. 14, 1964 These and other objects of the invention will become apparent upon reading the following detailed description of the invention in conjunction with the accompanying drawing wherein:

FIGURE 1 is an elevational view of an electromagnetic relay which utilizes the present invention.

FIGURE 2 is a view taken from the right of FIGURE 1 wherein a portion has been broken away to show the present invention.

FIGURE 3 is a top view of the armature of the relay drawn to an enlarged scale to better show the present invention.

Referring to FIGURES 1 and 2, the reference numeral it) generally designates an electromagnetic relay substantially of the type described in Patent No. 2,241,838, issued to John M. Wilson on May 13, 1941. Relay 19 comprises a U-shaped member 11 which is formed from a plate of magnetic material. When formed into the U-shape which it assumes in the present relay, member 11 defines leg portions 12 and 13 and a center or bight portion 14. Secured to the bight portion 14 of U-shaped member 11, between leg portions 12 and 13, is a laminated core 15 and a bobbin 16 which is made of plastic or other suitable material. Members 15 and 16 are secured to the U-shaped member 11 by appropriate means such as bolt 17. A shading ring 18, made of material such as copper, surrounds part of core 15 at its upper end. A coil 19 is wound around bobbin 16 and is connected to an electrical source (not shown) through a pair of terminals Zil, one of which is shown in the drawing. Terminals 20 are attached to extending or leg portions 21 of the bobbin 16.

A frame member 22 of insulative material such as plastic partially encloses leg 13 and is attached thereto by appropriate means such as screw 23. Also attached to leg 13 by screw 23 is a second frame member 24 of a similar insulative material. Frame member 24 is L-shaped and has one leg lying along frame member 22 and a second leg extending across the top of the relay and spaced a substantial distance above the upper end of core 15. A plurality of electrically conductive blades 25 are sandwiched between frame members 22 and 24. These blades are formed in a substantially L'shape such as is frame member 24, and extend beneath the upper leg of frame member 24 and somewhat beyond the end of that leg. Contacts 26 are formed on this extended end of blades 25. Blade members 25 are further adapted at their lower end 27 to be connected into an electrical circuit.

Extending from the upper or extended end of leg 12 are projections 3t and 31 which are of a generally rectangular shape and are relatively narrow compared with the over-all width of leg 12. Projections 30 and 31 are further characterized as being of a generally rectangular cross section to provide sides which act as bearing surfaces for portions of an armature member to be described later herein.

An armature member 32 has apertures 33 and 34 which are designed to accept projections 30 and 31 of leg 12, to provide a hinge action between armature 32 and leg 12. A third frame member 35 of a plastic or other insulative material is attached to armature 32 by appropriate means such as rivet 36 which extends through aperture 37 of armature 32. Attached to the extending end of frame member 35 are a plurality of electrical shorting bars 38 which are adapted to engage contacts 26 upon energization of coil 19 and movement of armature 32 to a closed position. Shorting bars 33 thereby close an electrical circuit through the contacts.

Referring to FIGURE 3, armature 3-2 is of a generally rectangular shape. Aperture 3 3 and 34 are located near one end thereof, and are further located near the outside 3 edges of the armature. Since apertures 33 and 34 in armature =32 are similar, reference numerals for aperture 34 :are also similar to those in 33 except that they have been primed. Due to the similarity between the two apertures only aperture 33 Will now be described.

Aperture 33 is of a generally rectangular shape, but has extending into it from the armature, rounded portions 40, 41 and 42 on three sides thereof. While these extending portions are described as rounded, they are of a very small radius and it must be pointed out that they have been rounded merely because of ease of forming, and they might well be of a triangular or pointed shape rather than rounded. Projections 40 and 41, which are diametrically opposite within the aperture 3 3, engage the opposite sides of projection 30 of leg 12 in a substantially point contact relationship and thereby provide a hinge action between armature 32 and leg 12. Projection 42, which extends into aperture 33- from a side which is substantially perpendicular to the sides from which projections 4i! and 41 extend, engages an edge of the extension 3%. it will be noted that projections 42 and 42' coact to locate transversely the armature with relationship to leg 12. These portions, 42 and 42, are also rounded so that they engage the extensions of leg 12 in a substantially point contact relationship and thereby reduce frictional effects.

As pointed out previously, apertures having only a rectangular shape without the present projections extending thereinto have been found to be unsatisfactory due to high residual magnetism and friction in the unit. These rectangular holes therefore would not provide the operation of the unit obtained through the use of a separate hinge. However, these undesirable effects have been overcome by the use of rounded portions 4%, 41 and 42 which provide substantially point contact engagement between the armature 32 and the extension 39.

Armature 32 has formed at the extreme end thereof a small projection in which an aperture 43 is provided. This aperture accepts one hooked end of a spring 44 which is connected at its opposite end to a member 45. Member 45 is fixed between bobbin 16 and the bight portion of U-shaped member 11 by bolt 17 and extends through an aperture in leg 12 and is provided with an aperture at the extended end thereof to accept a second hooked end of spring 44. Spring 44 normally biases the armature to an open position, being defined as a position wherein the at-mature is pivoted away from the core 15.

Referring again to FIGURE 1, it will be seen that a magnetic circuit is defined by the magnetic core 15, the bight portion 14, and leg 12 of U-shaped member 11, and the armature 32. Upon energization of coil 19, and hence introduction of magnetic flux into the aforesaid circuit, armature 32 and its attached frame member 35 are pivoted downward so that the armature engages core 15. This in turn causes closing of contacts 26 by shorting bars 33. Upon de-energization of coil 19, spring 44 returns armature 32 and frame member 35 to an open position as is shown in the drawing.

The use of apertures 33 and 64 in cooperation with the extended portions '30 and 31 of leg 12 provide a hinge action wherein there is very little frictional effect because of the substantially point contact engagement between the two elements. Likewise, the portions 42 and 42' which limit the transverse movement of armature 32 with respect to leg 12 also have. very little frictional effect because of their substantial point contact engagement with the extended portions of leg 12. The use of the novel apertures also reduces the residual magnetism effects which were heretofore objectional in arrangements which eliminated the use of a separate hinge member.

In summary, it is therefore seen that my invention provides a novel hinge arrangement which results in a substantial cost reduction in the production of a relay as described previously. The use of this novel hinge arrangement further eliminates the objectionable effects of residual magnetism previously encountered in an arrangement whereby the separate hinge member was eliminated.

While I have shown a specific embodiment of my invention used in a relay, it is to be understood that this is for illustrative purposes only and that obviously it will find utility in other devices. It is further to be understood that the invention is to be limited only by the scope of the appended claims.

I claim as my invention:

1. In an electromagnetic actuating device having a magnetic circuit including a magnetic member, means for inducing magnetic flux in the magnetic circuit, and a movable armature member hinged on one end of the magnetic member and completing the magnetic circuit, the improved armature hinge construction comprising: a plurality of projections each having at least two substantially parallel sides and extending from said one end of said magnetic member; a like plurality of corresponding apertures in said armature, each receiving one of said projections; and a pair of rounded portions of small radius extending inwardly from opposite sides of each of said apertures and cooperating with said two substantially parallel sides of the corresponding projection on said magnetic member and providing substantially point contact engagement therewith to afford hinge action between said armature and said magnetic member.

2. In an electromagnetic actuating device having a magnetic circuit including a magnetic member, means for inducing magnetic flux in the magnetic circuit, and a movable armature member hinged on one end of'the magnetic member and completing the magnetic circuit, the improved armature hinge construction comprising: a plurality of projections each having two substantially parallel fiat sides and extending from said one end of said magnetic memer; a like plurality of corresponding apertures in said an'nature, each receiving one of said projections; and a pair of diametrically opposed rounded portions of small radius extending inwardly from the periphery of each of said apertures and cooperating with said substantially parallel flat sides of the corresponding projection on said magnetic member and providing substantially point contact engagemen therewith to afiord hinge action between said armature and said magnetic member.

3. In an electromagnetic actuating device having a magnetic circuit including a magnetic member, means for inducing magnetic flux in the magnetic circuit, and a movable armature member hinged on one end of the magnetic member and completing the magnetic circuit, the improved armature hinge comprising: a plurality of projections of substantially rectangular cross section extending from said one end of said magnetic member; a like plurality of corresponding apertures in said armature and receiving said projections; a pair of oppositely disposed rounded portions of small radius extending inwardly from the periphery of each of said apertures and cooperating with a pair of substantially parallel flat sides of the corresponding projection on said magnetic member and providing substantially point contact engagement therewith to afiord hinge action between said armature and said magnetic member; and a third similar rounded portion extending from said armature into'each of said apertures and engaging a third side of the corresponding projection. in a substantially point contact relationship to limit transverse movement. of said armature with respect to said magnetic member.

4. In an electromagnetic relay having a magnetic circuit including a magnetic member, means for inducing mag- 'netic flux in the magnetic circuit, and a movable armature member hinged on one end of the magnetic member and completing the magnetic circuit, the improved armature hinge construction comprising: a plurality of projections of substantially rectangular cross section extending from said one end of said magnetic member; a like plurality of corresponding apertures in said armature, each receiving one of said projections; a pair of diametrically opposed rounded portions of small radius extending inwardly from the periphery of each of said apertures and cooperating with a pair of substantially parallel flat sides of the corresponding projection on said magnetic member and providing substantially point contact engagement therewith to afford hinge action between said armature and said magnetic member; and a third similar rounded portion extending inwardly from the periphery of each of said apertures in a direction substantially perpendicular to said pair of portions, said third rounded portion engaging a third side of the corresponding projection in a substantially point contact relationship to limit transverse movement of said armature with respect to said magnetic member.

References Cited in the file of this patent UNITED STATES PATENTS Witt June 29, Wilson May 13, Seeley Mar. 10, Field Ian. 27, DeFligue Mar. 18, Lace Oct. 21, Sauer Apr. 14, Dennison et a1 Apr. 12,

FOREIGN PATENTS Great Britain Sept. 21, 

1. IN AN ELECTROMAGNETIC ACTUATING DEVICE HAVING A MAGNETIC CIRCUIT INCLUDING A MAGNETIC MEMBER, MEANS FOR INDUCING MAGNETIC FLUX IN THE MAGNETIC CIRCUIT, AND A MOVABLE ARMATURE MEMBER HINGED ON ONE END OF THE MAGNETIC MEMBER AND COMPLETING THE MAGNETIC CIRCUIT, THE IMPROVED ARMATURE HINGE CONSTRUCTION COMPRISING: A PLURALITY OF PROJECTIONS EACH HAVING AT LEAST TOW SUBSTANTIALLY PARALLEL SIDES AND EXTENDING FROM SAID ONE END OF SAID MAGNETIC MEMBER; A LIKE PLURALITY OF CORRESPONDING APERTURES IN SAID ARMATURE, EACH RECEIVING ONE OF SAID PROJECTIONS; AND A PAIR OF ROUNDED PORTIONS OF SMALL RADIUS EXTENDING INWARDLY FROM OPPOSITE SIDES OF EACH OF SAID APERTURES AND COOPERATING WITH SAID TWO SUBSTANTIALLY PARALLEL SIDES OF THE CORRESPONDING PROJECTION ON SAID MAGNETIC MEMBER AND PROVIDING SUBSTANTIALLY POINT CONTACT ENGAGEMENT THEREWITH TO AFFORD HINGE ACTION BETWEEN SAID ARMATURE AND SAID MAGNETIC MEMBER. 